Prediction of in vitro gas production parameters of concentrate feeds by near infra-red reflectance spectroscopy (NIRS)

Herrero et al. (1996) found that NIRS was able to calibrate and cross-validate the static values of gas produced from the incubation of Kikuyu grass using manual in vitro gas production. However, the fermentation kinetic coefficients were not calibrated satisfactorily by NIRS. The aim of this study was to investigate the potential of NIRS as a means of predicting fermentation and the France et al. (1993) model parameters obtained from the automated in vitro gas production experiments for a range of concentrate feeds.Thirty-eight milled (1 mm) samples representing three typical concentrate feed types were scanned over the infra-red region covering 1100 to 2300 nm using an NIRS systems 6500 spectrometer. Optical data recorded as log 1/Reflectance were transformed to their standard normal variates and detrended values (SNV-D).